The present invention relates to parallel processor systems in which a plurality of processors share a storage in common. More particularly, the present invention is directed to a parallel processor control method and system suited for synchronization control among processors that is based on interdependence between data in caches and data in the storage.
Synchronization control among a plurality of processors in a storage-shared parallel processor system includes start synchronization control that assures simultaneous start of all the processors, end synchronization control that assures the end of a process executed by each processor, and barrier synchronization control that assures storage access sequencing among the processors. Each processor has a cache for storing data copied from the storage, and when the processors process data on which they are dependent among themselves, the system must effect the start, end and barrier synchronization controls, considering coherency between the caches and storage (cache coherency).
How start, end and barrier synchronization instructions are processed serially in parallel data processing while maintaining coherency between cache data and storage data is the problem to be solved in improving parallel processing performance.